Lockout arrangements for surgical instruments

Abstract

A surgical instrument including a first jaw that is configured to support a staple cartridge therein. An axially movable firing member is configured to move between a beginning position and an ending position by a first flexible drive member and a second flexible drive member. A firing member lock is configured to prevent the firing member from distally moving from the beginning position to the ending position unless an axially movable camming member in the staple cartridge that is supported in the first jaw is in a starting position.

1 - 20 . (canceled) 
     
     
         21 . A surgical tool, comprising:
 an end effector comprising an elongate channel and an anvil, wherein a lock cavity is defined into the elongate channel;   an shaft defining a longitudinal axis, wherein a yaw axis and a pitch axis are oriented transverse to the longitudinal axis;   a joint, wherein the end effector is articulatable about the yaw axis and the pitch axis at the joint;   a beam head movable distally through a closure stroke from a proximal position to an intermediate position to close the end effector and movable distally through a firing stroke from the intermediate position to a distal position, the beam head comprising:
 a first cam positioned to cammingly engage the elongate channel; and 
 a second cam positioned to cammingly engage the anvil; and 
   a blocker movable relative to the beam head and the lock cavity, wherein the blocker is movable between a blocking position and an unblocking position, and wherein the blocker, in the blocking position, is positioned to block distal advancement of the beam head through the firing stroke.   
     
     
         22 . The surgical tool of  claim 21 , wherein the blocker, in the blocking position, is positioned to block distal advancement of the beam head past the intermediate position such that the beam head is movable through the closure stroke to the intermediate position to close the end effector regardless of the position of the blocker. 
     
     
         23 . The surgical tool of  claim 21 , wherein the blocker comprises a spring-loaded blocker, and wherein the spring-loaded blocker is biased toward the blocking position by a spring. 
     
     
         24 . The surgical tool of  claim 23 , further comprising an unfired staple cartridge removably positioned in the elongate channel, wherein the unfired staple cartridge is structured to move the blocker from the blocking position to the unblocking position. 
     
     
         25 . The surgical tool of  claim 24 , wherein the unfired staple cartridge comprises a plurality of staples and a sled comprising a ramp movable to eject the plurality of staples, wherein the sled is structured to move the blocker from the blocking position to the unblocking position. 
     
     
         26 . The surgical tool of  claim 21 , wherein the position of the beam head over the lock cavity in the intermediate position is maintained regardless of a presence or an absence of an unfired staple cartridge in the elongate channel. 
     
     
         27 . The surgical tool of  claim 21 , wherein the beam head further comprises a distal-facing abutment surface structured to receive a blocking force via the blocker to prevent distal advancement of the beam head unless an unfired staple cartridge is positioned in the end effector. 
     
     
         28 . The surgical tool of  claim 21 , further comprising a plurality of pushers to push the beam head distally through the closure stroke and the firing stroke, wherein each pusher extends through the joint to the beam head. 
     
     
         29 . The surgical tool of  claim 28 , wherein the plurality of pushers comprises an upper pusher and a lower pusher. 
     
     
         30 . The surgical tool of  claim 29 , wherein the upper pusher and the lower pusher each comprise a pusher coil extending through the joint to the beam head. 
     
     
         31 . The surgical tool of  claim 29 , wherein the upper pusher and the lower pusher are vertically spaced apart within the shaft. 
     
     
         32 . A surgical tool, comprising:
 a shaft;   an end effector coupled to the shaft at an articulation joint, wherein the end effector is rotatable relative to the shaft at the articulation joint in a plurality of articulation planes, wherein the end effector further comprises a channel to support a staple cartridge, and wherein a lock cavity is defined in the channel;   a beam head comprising an upper cam and a lower cam, wherein the beam head is movable distally through a closure stroke from a proximal position to an intermediate position to close the end effector and movable distally through a firing stroke from the intermediate position to a distal position; and   a spring-loaded blocker movable relative to the beam head and the lock cavity, wherein the spring-loaded blocker is biased toward a blocking position, and wherein the spring-loaded blocker, in the blocking position, is positioned to block distal advancement of the beam head through the firing stroke.   
     
     
         33 . The surgical tool of  claim 32 , further comprising an unfired staple cartridge removably positioned in the end effector, wherein the unfired staple cartridge is structured to move the blocker from the blocking position to an unblocking position. 
     
     
         34 . The surgical tool of  claim 33 , wherein the unfired staple cartridge comprises a plurality of staples and a sled comprising a ramp movable to eject the plurality of staples, wherein the sled is structured to overcome a spring force to shift the spring-loaded blocker from the blocking position to an unblocking position. 
     
     
         35 . The surgical tool of  claim 34 , wherein the spring-loaded blocker is compressed into the lock cavity by the sled of the unfired staple cartridge. 
     
     
         36 . The surgical tool of  claim 33 , wherein the vertical position of the beam head over the lock cavity in the intermediate position is maintained regardless of a presence or an absence of an unfired staple cartridge in the end effector. 
     
     
         37 . The surgical tool of  claim 33 , wherein the beam head further comprises a distal-facing abutment surface structured to receive a blocking force via the spring-loaded blocker to prevent distal advancement of the beam head unless an unfired staple cartridge is positioned in the end effector. 
     
     
         38 . The surgical tool of  claim 33 , wherein the spring-loaded blocker is resiliently supported in the channel. 
     
     
         39 . The surgical tool of  claim 33 , further comprising a plurality of pushers to push the beam head distally through the closure stroke and the firing stroke, wherein each pusher extends through the articulation joint to the beam head, wherein the plurality of pushers comprises an upper pusher and a lower pusher, and wherein the upper pusher and the lower pusher are vertically spaced apart within the shaft. 
     
     
         40 . The surgical tool of  claim 39 , wherein the upper pusher and the lower pusher each comprise a pusher coil extending through the articulation joint to the beam head.